This invention relates to a silicone bag assembly for use in pharmaceutical manufacturing and for holding health care related solutions and, more particularly, to apparatus for manufacturing such a bag assembly.
At the present time, virtually all bags used by the pharmaceutical industry and for holding health care related solutions (such as intravenous bags) are manufactured of polyvinyl chloride (PVC). PVC is a commonly used inexpensive plastic material which is naturally hard. To soften such material so that it can be used as a flexible bag and as flexible tubing, plasticizers such as phthalate esters are added to the PVC to soften it. Recently there has been concern that phthalates may leach from the PVC to which they have been added, thereby contaminating aqueous fluids held in PVC bags and traveling through PVC tubing. Since PVC bags are used to store intravenous solutions and blood for transfusions, phthalates which leach from the PVC are infused directly into a patient""s bloodstream. It has therefore been proposed to form the bag and tubing from silicone, which does not react with contacting liquids or leach chemicals into contacting liquids. Accordingly, a need exists for apparatus capable of manufacturing such a bag assembly, particularly in a continuous production process.
According to the present invention, the bag assembly is formed from a tube and a tubular flexible membrane with opposed open ends. The basic inventive apparatus includes a base for supporting the membrane and the tube with the tube extending into one of the membrane open ends, a first clamp adapted to flatten and clamp the membrane to itself and to the tube along a line spaced from and substantially parallel to the open end, an injector adapted to inject liquid adhesive into the open end and around the tube between the open end and the line, and a second clamp adapted to flatten and clamp the membrane to itself and to the tube between the line and the open end. Accordingly, the first clamp is operative to prevent injected adhesive from getting into the interior of the tubular membrane.
Using the aforedescribed basic apparatus, a continuous production manufacturing apparatus is provided including a pair of endless belt systems arranged for movement in opposite angular directions. The first belt system includes a plurality of bases mounted thereon at a plurality of equally spaced locations. The second belt system has mounted thereon a plurality of the first and second clamps and is dimensioned to expose a leading portion of the first endless belt system. The clamps are arranged so that each first clamp is spring coupled to the second endless belt system so as to be yieldably biased away from the second endless belt system. The clamps are arranged so that the first clamp contacts a respective base before the second clamp contacts that base. A membrane placement station is arranged to place a respective flexible membrane on each base while that base is exposed, and a tube insertion station is arranged to insert a tube into such a placed membrane. An adhesive injection station is arranged to inject liquid adhesive into the open end of each membrane while on its respective base with a respective tube inserted therein while a first clamp contacts the membrane but before a second clamp contacts the membrane. After the second clamp contacts the membrane, the clamped assembly cures while travelling along the belt systems. The clamps later separate from the bag assembly, which falls off the trailing end of the first endless belt system.